In general, diesel fuel starts to become cloudy at temperatures around -10 to -15 degrees Celsius (14 to 5 degrees Fahrenheit). This is known as the "cloud point" and indicates the formation of small wax crystals within the fuel. As the temperature drops further, the wax crystals grow in size and eventually block the fuel filter, preventing the engine from receiving a sufficient supply of fuel.
The actual freezing point of diesel, where it becomes solid and ceases to flow, is typically around -20 to -30 degrees Celsius (-4 to -22 degrees Fahrenheit). However, some blends may freeze at even higher temperatures, while others may remain liquid at lower temperatures.
It's important to note that the freezing point of diesel fuel can be influenced by the presence of additives, such as anti-gel agents, which are commonly added to winter-grade diesel to lower the pour point and improve cold-flow properties.
